ISOLATION, IDENTIFICATION AND SAFETY PROFILING OF POTENTIAL PROBIOTIC LACTIC ACID BACTERIA FROM INDIGENOUS FOOD PLANTS IN ILOCOS SUR

Abstract

This study investigated lactic acid bacteria (LAB) associated with Indigenous Food Plants (IFPs) of Ilocos Sur-Yacon (Smallanthus sonchifolius), Tebbeg (Ficus nota), and Allagat (Uvaria rufa)-through isolation, characterization, molecular identification, and safety evaluation. Samples were enriched in MRS broth, which yielded the highest LAB recovery, followed by serial dilution and plating. Out of 83 isolates, ten were selected based on Gram-positive, catalase-negative, and typical LAB morphology. All isolates exhibited non-hemolytic activity, indicating favorable safety profiles, while antibiotic susceptibility tests revealed significant variation (p < 0.001), with several isolates showing comparable or higher susceptibility than the Lactiplantibacillus plantarum ATCC reference strain. 16S rRNA gene sequencing revealed high sequence similarity (96.11–100%), identifying the isolates as Enterococcus spp., Pediococcus pentosaceus, Streptococcus Suis, and Lactiplantibacillus plantarum. The generated sequences were deposited in the NCBI GenBank  database under accession numbers PZ235148, PZ231870, PZ231868, PZ231865, PZ231791, PZ231582, PZ231487, and PZ231317. Phylogenetic analysis using the Maximum Likelihood method confirmed clear clustering consistent with BLAST results. Notably, ISPSC-AL8B grouped with Pediococcus pentosaceus, while ISPSC-XY13 clustered within the Lactiplantibacillus plantarum lineage. Overall, the results confirm the successful identification of LAB from IFPs and highlight selected isolates as potential candidates for probiotic and food biotechnology applications.